Winter is fast approaching, and even though autumn in a polytunnel can make it seem like the coldest months are still a world away on sunny days, frosts now threaten and if you have not already done so, it vitally important to be prepared. Preparing your polytunnel for cold weather is a simple but vital process. Here are some of the things that you should do now before it is too late:
Consider Methods for Heating Your Polytunnel
While an unheated polytunnel can still be used to grow a wide range of produce even over the winter months, you might like to consider heating your polytunnel. Now could be a good time to arrange a new polytunnel heating system to grow more tender plants, or to create an outdoors living area that you can use all year round. For example, you could consider solar powered electric heating, a rocket mass stove, or another eco-friendly option.
Add Mini Polytunnels, Row Covers or Cloches Inside Your Polytunnel
Protecting plants growing in your polytunnel from frost is often simply a case of giving them an extra layer of protective covering. You can consider using mini polytunnels, row covers, bubble wrap, horticultural fleece or other fabrics, or even simple cloches made from plastic food packaging to protect individual plants.
Improve Thermal Mass Before Cold Weather Arrives
Another way to give your plants a little extra protection from cold weather is to improve the thermal mass inside your polytunnel. This can help to keep your polytunnel a little warmer during cold winter nights. Stone or brick, concrete, clay or ceramics can all be used for paths, bed edges or staging in your polytunnel. You can also store rainwater inside your polytunnel. Materials such as these will catch and store the sun’s heat during the day and release it slowly once temperatures fall.
Mulch To Protect Plant Roots From Cold Weather
A polytunnel will keep plants warmer than those grown outside, but even so, in cold weather, the inside of a polytunnel can still drop below zero, which can cause damage to plants and their root systems. Another way to prepare and to keep roots warm is to cover them with a protective layer of mulch, such as bracken or straw.
Create a ‘Hot Bed’ for Cold Weather Warming
As cold weather approaches, you can consider growing tender plants on a hot bed. Hot beds are beds built up with composting straw and other organic materials. As they decompose, these materials will give of a surprising amount of heat, which can help to keep cold weather at bay.
Check out out other articles and guides to learn more about preparing for cold weather and keeping plants happy in your polytunnel throughout the whole year. Let us know how you prepare your polytunnel for winter in the comments below.
Elizabeth Waddington is a writer and green living consultant living in Scotland. Permaculture and sustainability are at the heart of everything she does, from designing gardens and farms around the world, to inspiring and facilitating positive change for small companies and individuals.
She also works on her own property, where she grows fruit and vegetables, keeps chickens and is working on the eco-renovation of an old stone barn.